COD Removal from Soft Drink Industrial Wastewater Using a Pilot-Scale ICX Reactor with Life Cycle Assessment via OpenLCA: A Case Study in West Tehran

The rapid growth of industrial wastewater generation and the concurrent scarcity of freshwater resources underscore the need for efficient and environmentally sustainable treatment technologies. This study evaluated the performance of a pilot-scale Internal Circulation expanded (ICX) anaerobic reactor for the removal of chemical oxygen demand (COD) from the wastewater of a soft drink factory in the western industrial zone of Tehran, and compared its environmental footprint with the existing membrane bioreactor (MBR) system using life cycle assessment (LCA). The ICX reactor was operated continuously under real on-site conditions for two months. The average COD removal efficiency was ۸۶% _x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰_(_x۰۰۰۰_mean _x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰_SD), with effluent concentrations consistently below ۱,۵۰۰ mg/L. Kinetic analysis under plug-flow and first-order assumptions yielded an apparent reaction rate constant k of ۰.۱۸ day (R_x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰_۲ ۰.۹۲-۰.۹۸), and ANOVA confirmed a significant difference (p < ۰.۰۵) between the start-up and stable operation phases. The LCA, performed with OpenLCA and the Recipe ۲۰۱۶ Midpoint (H) method for a functional unit of ۱ m_x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰__x۰۰۰۰_۳ treated wastewater, revealed that integrating the ICX reactor as a pre-treatment to the MBR system reduced global warming potential by ۲۷%, freshwater eutrophication potential by ۳۴%, and human toxicity potential by ۱۸%, primarily due to biogas energy recovery and reduced chemical and sludge footprints. The results demonstrate that the ICX-MBR configuration is a technically robust and environmentally superior option for high-strength beverage wastewater, with clear potential for full-scale industrial deployment.

کلیدواژه ها:

ICX reactor ، anaerobic treatment ، industrial wastewater ، soft drink factory ، COD removal ، kinetic modeling ، life cycle assessment